Synchro-shifting transmission clutch



May 23, 1944. DUGAs Q 2,349,491

1 SYNGHRO-SHIFTING TRANSMISSION CLUTCH Filed Dec. 1, 1942 I 2Sheets-Sheet l May 23, 1944. J. J. DUGAS SYNCHRO-SHIFTING TRANSMISSIONCLUTCH 2 Sheets-Sheet 2 Filed Dec. 1, 1942 humed May 23, 1944 I2,349,491

Joseph J. Dugas, New Orleans, La, assignor to Higgins Industries, Inc;,New Orleans, La.,a corporation of Louisiana Application December 1,1942, Serial him-167,520

1 Claim.

This invention relates to a synchronized transmission clutch,particularly designed for marine installations in which-it is customaryto have the propeller rotate at substantially the same number of R. P.M. in reverse as in forward direction whereby to employ the propeller inreverse as an efllcient brake.

One of the objects of the invention is to provide a transmission clutchwhich engages the driving and driven members, both for forward andreverse operation, frictionally in the initial movement wherebythedriven member is brought up smoothly to the speed of the driving member,and

then positively, in the subsequent movement, so

eter which extends into a bore 8 in the adjacent end of the drivingshaft I, a sleeve bearing 9 of suitable wear resisting materialintervening. The driving and driven shafts, as shown, are coaxial andnormally relatively rotatable.

The driving shaft I is provided with a zone of splines I0 overlying thatregion in which the driving shaft surrounds the driven shaft. A movableclutch member, which as a whole is designated by the reference characterI I, is mounted upon the driving shaft slidably upon the splines Hi androtates with the driving shaft. The movable clutch member ll consistsessentially of two parts, the drum l2 and the peripheral sleeve l3.

that positive engagement is efiected by a single The drum H is providedon its outer circumfermovement of the operatinglever without noise orence with a series of spline teeth H, '(see Figure clash of theinterengaging mechanisms and with- 2), and the peripheral sleeve I3 isprovided on out requiring any timing judgment on the part of its innercircumference with a series of spline the operator. This is extremelyimportant in reteeth It which interdigltate with the spline teethversing, for it is frequently necessary to put the 29 M, so that theperipheral sleeve I3 is rotatable boat in reverse suddently, to avoidcollision, with the drum it, but slidable in either direction which act,in a positively engaging clutch is apt relative to saidclrum. to resultin stripping of gears or in failure of the The drum is provided withradial bores [16 clutch to engage at all, in the absence of the openingin its circumferential surface and housinitially acting frictionalsynchronizing means. ing the spring projected detents ll which engageOther objects of the invention will appear as in depressions l8 formedin the outer circum the following description oi a preferred andferential surface of the drum it. Thus normalpractical embodimentthereof proceeds. ly, the peripheral sleeve it resists lateral dis- Inthe drawings which accompany and form placement until the pressure ofthe detents ll a part of the following specification, and to has beenovercome. On both sides, the drum. throughout the several figures ofwhich the some 32 is provided with annular depressions ill withreference characters have been employed to ace inwardly convergent wallsto and 2| which serve ignate identical parts: as friction faces for themovable member of the Figure l is a longitudinal vertical cross-sectionclutch. The peripheral sleeve it is provided on through asynchro-shiftlng transmission clutch 35 its outer circumference with thespaced'ribs 22, embodying the features of the subject invention; formingbetween them an annular channel 23 Figure 2 is a cross-section takenalong the line which receives the arcuate yoke 24 at the lower 2-2 ofFigure 1; end of the clutch operating lever 25, the latter I Figure 3 isa cross section taken along the line being pivoted at the intermediatepoint 28 to the 3I of Figure 1; and 40 housing 6.

Figure 4 is a fragmentary detail partly in sec- It will be obvious fromthe above description tion, showing the chamiered ends of the interofthe movable clutch member 5 i that when the engaging teeth by which theclutch is positively lever 25' is shifted either to the right or left,as engaged. V I viewed in Figure 1, the movable clutch member Referringnow in detail to the several figures, will first move as a whole andthen when resistthe numerals i and 2 represent, respectively, the oncehas been encountered to its further movedriving and driven shafts, theformer being promerit, the pressure of the detent will be overcome videdwith the splined zone 3 by which it is conand the peripheral sleeve I 3will move laterally nected to the internal combustion engine of therelative to the drum l2. marine power plant, and the'latter having a '50The movable clutch member ii is flanked 0n threaded end l by means ofwhich it is connected both sides by thecomplementary clutch memto thepropeller shaft coupling. The driven bers 21 and 28, the former beingemployed for theft 2 is carried in a bearing 5 in the transforwarddrive, and the latter for reverse. Each mission housing 6. The forwardend of the of these clutch members comprises a-flange 35 driven shaft 2has a portion 1 of reduced diamand 36, respectively, having therespective external teeth 29 and 30, said flanges being of such diameterthat the teeth 29 and til are in alignment with the spline teeth iii ofthe peripheral sleeve l3 so as to be engaged by said spline teeth whenthe peripheral sleeve l3 slides beyond the drum l2 when released fromthe detents ii. The complementary clutch members 27 and it also have therespective annular ribs 35 and 32 with outwardly convergent walls 33 and3 3 tapered to correspond to the walls 25 and 22E of the movable clutchmember and adapted to frictionally engage said walls when the movableclutch member is shifted into contact with either of the comple vmental-y clutch members. The frictionally engaging portions of themovable and complemen= tary clutch members are so constructed that whenthey are in full frictional engagement the gear teeth 29 and 3@ on thecomplementary clutch members are still laterally spaced from the splineteeth 55 of the peripheral sleeve l3, allowing a brief time interval toautomatically elapse between the full frictional engagement position ofthe movable and complementary clutch members and the positive engagementof the peripheral sleeve it with the teeth #29 or to.

The flange 35 is formed at'the inner end of a hub 3i fixed to the drivenshaft 2, and which is unitary with a gear 3%. The flange 36 is formed atthe inner end of a gear 39 which is rotatably mounted on the drivingshaft on a hearing it. The gear 39 is permanently in mesh with a gear llfixed to the lay shaft 32, which lay shaft also carries a gear at fixedthereto, which last named gear is connected through an idler M to thegear 38 fixed to the driven shaft. When the movable clutch member it isin engagement with the complementary clutch member 2?, the driven shaftis directly driven. When the movable clutch member ii is in engagementwith the complementary clutch member 28, the driving torque istransmitted through the gears 39 and M, lay shaft 42, gears 33, tit and38 to the driven shaft. The interposition of the'idler gear ti reversesthe directionof rotation of the driven shaft. It will be noted that thegears 3t and d3 have a one to one relation, as do also the gears 39 andM, so that in the illustrated embodiment of the invention there is nogear reduction in reverse and the propeller rotates with the same numberof R. P. M. in reverse direction as in the forward direction.

In operation, assuming that the operating lever is shifted to the leftinFigure 1, which is the reverse direction, the movable clutch member Hmentary clutch member 28 which can move no further, so that furthermovement of the operating lever 25 in a reverse direction overcomes thepressure of the detents ll so that the peripheral sleeve l3 moves out tothe right, as viewed in Figure 1, the spline teeth 15 coming into meshwith the teeth 30 on the gear 36. This will positively engage thedriving and driven members of the clutch.

In a marine installation, a positively coupled tion clutch varies, dueto the weaving of the hull panied by noise and clash of the gears.

as the waves pass beneath it. When the hull bridges two waves, it weavesdownwardly in the middle. When a single wave is beneath .the middle andthe ends unsupported it weaves upwardly. This weaving creates slightfluctuations in the distance between the internal combustion engine andpropeller and creates variations in clutchpressure which causes frequentslippage of a friction clutch. This objection is obviated by theemployment of a positively coupled clutch, but such a clutch has thedrawback that when it is attempted to suddenly engage it, the gears ofthe driving and driven elements may not be in alignment, and the clutchmay not engage at all. This is an extremely hazardous condition,particularly when the clutch lever is suddenly moved to reverse in theattempt to avoid collision. Stripping of the gears frequently occurs,and at all times unless the operator has an experienced timing judgment,the engagement of the clutch either in forward or reverse directions isaccom- All of this is obviated by having the clutch take holdirictionaliy in the initial movement of the operating lever andautomatically pass from frictional to positive engagement as soon as thespeeds of the driving and driven clutch elements have been fricticnallysynchronized.

Referring again to Figure 1, when it is desired to engage the clutch. inforward position, the operating lever is shifted to the right, themovable clutch element l l slides to the left until the drum isinfrictional engagement with the complementary clutch member 2l,-in whichposition the drum can move no further. Further continuing movement ofthe operating lever causes the peripheral sleeve it to overcome thedetents ll and move leftward until the spline teeth l5 engage the teeth29 of the gear 335. It will be noted from Figure 4 that the adjacentends of the sprine teeth to and the teeth on the respective gears 35 and3b are chamfered so that they will readily pass into mesh when thespeeds of the movable and complementary clutch members have beensynchronized.

While I have in the above description defined what I believe to be apreferred and practical embodiment of the invention, it will beunderstood to those skilled in the art that the specific details ofconstruction and arrangement of parts are by way of example and not tobe construed as limiting the scope of the invention as defined in theappended claim.-

What I claim as my invention is:

Synchro-shifting transmission clutch comprising normally relativelyrotatable axial driving and driven shafts, a. gear freely rotatableon'the driving shaft, a gear fixed to the driven shaft, said gears beingpermanently connected through a train of gearing including. a reverseidler and having a substantially one to one ratio, a slidable clutchmember between said gears splinably mounted on said driving shaft torotate therewith and. slide thereupon comprising a drum having annulargrooves of angular cross-section on opposite sides and a sleeve mountedabout the periphery of said drum having internal faces splinablyinterdigitatingwith external teeth on the periphery of said drum,whereby said sleeve is slidable laterally beyond either side of saiddrum, a spring detent normally maintaining said sleeve in fixedmid-position to said drum, said gears being parts of respectivecomplementary clutch members each including .an annular flange ofangular cross-section positioned to be engaged by the adjacent frictionfaces of the adjacent annular groove of said drum, each clutch memberhaving teeth about its periphery positioned to be engaged by the teethof said sleeve when in laterally extended position, and an operatinglever for moving said clutch member into engagement with either of saidcomplementary clutch members whereby the friction faces of said drumfirst engage the corresponding friction faces of the complementaryclutch member, limiting the sliding movement of said drum, furthermovement of said operating lever in the same direction overcoming saiddetent and bringing the teeth of said sleeve into engagement with theteeth of the adjacent flange.

JOSEPH J. DUGAS.

